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Transcript of 1 Cnc Seminar
8/6/2019 1 Cnc Seminar
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SEMINAR
ON
I NTERPOLATION
&
CUTTER COMPENSATION
Presented By
L.MARIA IMMANUEL RICHARD2nd Semester M.Tech Tool Engineering
R V College Of Engineering
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G01 Linear Interpolation
N_ G01 X _ Y_ Z_ F_
� G01 command is specifically for the linear removal of material from a
workpiece, in any combination of the X, Y, or Z axes.
� This G code provides for straight line (linear) motion from point to point.Motion can occur in 1, 2 or 3 axes. All axis specified will start at the
same time and proceed to their destination and arrive simultaneously
at the specified feed rate.
� Because there is contact between the cutting tool and the workpiece, it
is imperative that the proper spindle speeds and feed rates be used.
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G01 Linear Interpolation
Example
N30 G01 Z-0.125 F5 feed Down to Z-0.125 at ipm
N35 X3 Y2 F10 feed diagonally to X3, Y2 at 10 ipm
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CIRCULAR INTERPOLATION
The programming method of controlling a tool path along an arc is
similar to the method of programming a tool path along a line.
The method of circular contouring is called circular interpolation.
It is commonly used in profiling on CNC vertical & horizontal
machining centres ,lathes,milling machines,wire EDM etc.
Circular interpolation is used for programming arcs or complete circles
in such applications as outside & inside radii,circular
pockets,spherical/conical shapes,corner breaks.
The CNC unit will interpolate a defined arc with high precision if the
necessary information is given in the program.
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ELEMENTS OF A CIRCLE
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PROGRAMMING FORMAT
The programming format for a circular interpolation tool
path must include several paramets without which the
task of cutting an arc would be impossible.
The important parameters are1. Arc cutting direction (CW/CCW).
2. Arc Start & End points.
3. Arc Centre & Radius value.
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G02 Circular Interpolation (CW)
I, J, K specify the radius
R specifies the radius
� The G02 command is used specifically for all clockwise radial
moves, whether they are quadratic arcs, partial arcs, or complete
circles, as long as long they lie in any one plane
ExampleN35 G02 X2 Y2 I1 J0 F20
N45 G02 X3 Y0.5 R2 F20
The G02 command requires an endpoint and a radius
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G02 Circular Interpolation (CW)
� An easy way to determine the radius values (I and J values) is by making
a small chart:Center Point X1 Y1
Start Point X1 Y2
__________________________
Radius I0 J-1
G02 X2 Y1 I0 J-1 F5
Result
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� Circular interpolation commands are used to
move a tool along a circular arc to thecommanded end position. Five pieces of
information are required for executing a
circular interpolation command:
G02 Circular Interpolation (CW)
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G02 Circular Interpolation (CW)
Example
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G02 CW CIRCULAR INTERPOLATION USING "I", &"J" FOR THE X & Y AXIS
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G02 CW CIRCULAR INTERPOLATION USING ³R´
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G03 Circular Interpolation (CCW)
N_ G03 X _ Y_ Z_ I_ J_ K_ F_
N_ G03 X _ Y_ Z_ R_ F_
I, J, K specify the radius
R specifies the radius
� The G03 command is specifically for all
counterclockwise radial feed moves, whether
they are quadratic arcs, partial arcs, or
complete circles, as long as they lie in any
plane.
Example
N40 G03 X3 Y3.5 I-0.5 J0 F20
N60 G03 X3.5 Y1 R0.5 F20
The G03 command requires an endpoint and a radius
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� An easy way to determine the radius values (I and J values) is by making
a small chart:
Center Point X2 Y1
Start Point X2 Y2
__________________________
Radius I0 J-1
G03 X1 Y1 I0 J-1 F5
Result
G03 Circular Interpolation (CCW)
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G03 Circular Interpolation (CCW)
Example
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G03 CCW CIRCULAR INTERPOLATION USING "I", &"J" FOR THE X & Y AXIS
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G03 CCW CIRCULAR INTERPOLATION USING ³R´
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Cutter Compensation
� Cutter compensation is used to offset the center of the cutter, and shift it
the distance of the radius, to the specified side of the programmed path.
� Complex part geometries having angled lines, lines tangent to arcs, and
lines intersecting arcs involve substantial trigonometric computations to
determine the center of the cutter.
� Cutter compensation involves
programming the part geometry directly
instead of the tool center.
� The cutter compensation commands are: Cutter Compensation Left (G41),
Cutter Compensation Right (G42), and
Cutter Compensation Cancel (G40).
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Cutter Compensation
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G41 Cutter Compensation Left
N_ G41 D_
� G41 will select cutter compensation left; that is the tool is moved to theleft of the programmed path to compensate for the radius of the tool.
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G42 Cutter Compensation Right
N_ G42 D_
� G42 will select cutter compensation right; that is the tool is moved to theright of the programmed path to compensate for the radius of the tool.
� A Dnn must also be programmed to select the correct tool size from the
DIAMETER/RADIUS offset display register.
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G40 Cutter Compensation Cancel
N_ G40
� G40 will cancel the G41 or G42 cutter compensation commands.� A tool using cutter compensation will change from a compensated
position to an uncompensated position.
� Be sure to cancel cutter compensation, when you're done with each
milling cut series that's using compensation.
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Cutter Compensation
� Understanding cutter compensation can be simplified if one has a basic understanding of
manual machining. There are two common types of cutting conditions associated with
milling machines. They are CLIMB and CONVENTIONAL cutting.
Two common rules for these types of cuts are:
� If the programmed cutter path
needs to mill CLIMB cutting, and if
it's a standard right handed tool, it
will then be programmed with G41cutter LEFT of the programmed
path.
� If the programmed cutter path needs to
mill with CONVENTIONAL cutting, and
it's a standard right handed tool, it will
then be programmed with G42 cutter RIGHT of the programmed path.
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Cutter Compensation Example
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Some Restrictions with Cutter Compensation
� A cutter compensation command (G41, G42 or G40) must be on the
same block with an X and/or Y linear command when moving onto or
off of the part using cutter compensation
� You cannot turn on or off cutter compensation with a Z axis move.
� You cannot turn ON or OFF cutter compensation in a G02 or G03
circular move, it must be in a linear G00 or G01 straight line move.
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THANK YOU